1. Field of the Invention
The present invention relates to a display apparatus having a mechanism for opening and closing a display panel.
2. Description of Related Art
A display apparatus having a main body and a display panel connected to the main body by a hinge has been known hitherto. In this display apparatus, the display panel is closed when it is not used, and it is opened to make an appropriate angle relative to the main body when the display panel is used. The angle between the display panel and the main body is adjusted to an appropriate angle to provide a best view to a user. The display panel is driven by a driving motor to open the display panel up to a desired angle. The opened display panel is held at the desired angle by a friction in a gear train disposed between the driving motor and the display panel. However, there is a problem that the display panel cannot be held exactly at the desired angle because there is a certain backlash in the gear train.
To cope with this problem, it has been proposed to give a large friction to a hinge connecting the display panel to the main body, or to give a biasing force to the display panel in one direction. The backlash in the gear train may be alleviated by a certain degree by employing these measures. However, it is necessary to use a large driving motor to overcome the large friction or the biasing force in driving the display panel. Further, JP-A-2004-237895 proposes to keep the driving motor to operate at a low torque when the display panel is opened to a desired position. In this manner, the backlash of the gear train is alleviated. However, the display panel has to abut a certain stopper against the low driving torque of the motor at the desired position. Accordingly, the opening angle of the display panel is limited to the position of the stopper, and it becomes difficult to arbitrarily set the opening angle according to a user's preference.